The present invention relates to a semiconductor module having a high cooling capability and a producing method thereof.
Conventionally, various cooling techniques for semiconductor modules, more particularly, LSI (Large Scale Integration) semiconductor modules have been proposed. For example, one such technique is described in an article entitled "NEW INTERNAL AND EXTERNAL COOLING ENHANCEMENTS FOR THE AIR COOLED IBM 4381 MODULE" in IEEE International Conference on Computer Design, 1983. In this technique, a small gap is present between a semiconductor chip (referred to as chip, hereinafter) mounted on a substrate and a cap opposite the chip. The cooling capability of the cap for the chip is largely influenced by the size of the small gap. That is, when the small gap is reduced, the heat resistance is decreased to enhance the cooling capability. In the above article, it was reported that when the small gap was kept to be 0.2 mm and a heat-conductive compound or a thermal paste was filled in the gap, the heat resistance between the chip and the cap was 9.degree. C./W.
However, in such an LSI semiconductor module, the substrate, chip, cap, and the like as constituents for the semiconductor module have dimensional errors, and a total of these errors and assembly errors amounts to 100 to 200 .mu.m. If the small gap is designed to be smaller than the total errors, the chip is undesirably brought into contact with the cap and they may be damaged. Therefore, in the conventional semiconductor module, it is difficult to reduce the small gap to be smaller than the total errors to attain reduced heat resistance, and hence, the module has a low cooling capability for the chip.